As we mentioned in 1.1 "On Truth", truth matters because it satisfies our curiosity. But that means we need to be curious in the first place! Good thinkers have a disposition to pursue the truth for its own sake, solely out of a desire to know and not simply for the potential advantages it might afford us. Having a curious disposition means you are motived by a desire to learn about the world around you. You genuinely care about, say, the experience of black folk in urban housing, or whether a messenger mRNA molecule can be used in vaccines to produce an immune response. Of course, in both of these examples what we learn might turn out to be quite useful for improving the lives of minority communities or protecting human communities generally from harmful viral infections. But if we’re curious, we will value learning about these things even if they don’t lead to useful outcomes, simply because discovering the truth about our world enriches our lives all by itself, and learning more about how different communities struggle to create spaces to call home, or how various biochemical molecules work, enrich our lives whether or not we can develop policies or technologies as a result.
Being motivated to learn for its own sake is important for how we think well with others. If all I care about is what my learning will get me, I will be tempted or biased to prefer evidence that favors the outcomes I want, or to discount evidence for the outcomes I oppose. Being curious helps to guard us against caring about truth only for its instrumental value, rather than its intrinsic value. Curiosity places our focus on the question or puzzle we’re interested in, and not on preserving a pre-determined position we already believe. The same goes for listening to other people. If I’m curious about how others see the world, it helps me to listen to their ideas and perspectives regardless of whether I can use what I learn to further my career or take advantage of them. Curiosity also helps us guard ourselves against manipulation; if we genuinely want to understand current events, we will be less interested in partisan or ideological news media and political commentary that “spins” events to serve a particular agenda.
Finally, curiosity is important as a virtue because it reminds us that making mistakes and being wrong is okay. The British-American philosopher Alfred North Whitehead wrote, “panic of error is the death of progress; and love of truth is its safeguard.” Making mistakes and judging falsely are not bad as long as we see them as part of the larger learning process. Mistakes give us an opportunity to figure out why we were mistaken, and make corrections accordingly. If we are curious, that is, if we are people motivated by a love of truth, then we will care more about the discovery process than the fact that we believed the wrong things along the way.
Intellectual honesty is the disposition to be truthful and sober in your assessment of your own knowledge. It’s easy to claim that we know things and even to have confidence in what we know, but often we find that on reflection we shouldn’t have as much confidence as we do. Confidence is cheap. What is of higher worth is the ability and disposition to recognize the things we don’t know or shouldn’t be confident in and the things that we do know and do have reason to be confident in. Much of what we think we know we think we know really because we read a headline while scrolling through Facebook or Twitter or someone told us once sort of off-handedly. These, when we think about it, aren’t very good sources of knowledge. They aren’t really grounds or justifications for our beliefs—or at any rate aren’t very good justifications for our beliefs. Intellectual honesty is the disposition to take a beat, think about why it is that we feel confident in a belief and feel ready to assert it, and then proceed with a more honest assessment of what we know and why we think we know it.
Intellectual humility goes hand in hand with intellectual honesty. What is means to be intellectually humble, though, is slightly different from being honest. Intellectual humility is a disposition to recognize that even when we have good grounds for knowing something, there might always be something that upsets that understanding or set of beliefs. To be intellectually humble is to remember that human beings have been very confident many times in the past and often for very good reason, but have turned out to be wrong due to some false assumption somewhere in their thinking. It’s the disposition to say “even if I have really good reason to believe what I believe, I still might be wrong.”
The Search for Vulcan
In the early 1800's, several astronomers including Alexis Bouvard noticed that the planet Uranus was not orbiting the sun in a manner consistent with current mathematical models about the laws of nature governing how planets move. This led Bouvard and another astronomer, Urbain Le Verrier, to postulate that there must be another planet in the vicinity whose gravitational pull was affecting the motion of Uranus. In 1846, using predictions sent to him by Le Verrier, Johan Gottfied Galle was able to spot a planet from the Berlin Observatory, which would become known as the planet Neptune.
Shortly after the discovery, Le Verrier turned his attention to Mercury, another planet that astronmers had trouble applying current physical predictions to. Le Verrier made a complete model of Mercury’s motion with predictions to be tested when Mercury was next scheduled to orbit across the face of the Sun in 1848. Mercury failed to move in accordance with Le Verrier’s predictions.
Rather than give up, Le Verrier spent the next decade creating some of the most rigorous and detailed calculations of the motion of Mercury to date, yet he could not come up with predictions that matched observation. Using inspiration from the successful prediction of Neptune as a planetary body affecting the motion of Uranus, Le Verrier predicted that there must be a planetary body affecting Mercury, and he postulated the existence of the planet Vulcan (same word that is used in some of the Star Trek stories!).
Over the rest of his life, Le Verrier worked with observatories to confirm the existence of Vulcan, and while many alleged sightings were reported, none came in that could be confirmed. He died in 1877, firmly believing that Vulcan was out there. It wouldn’t be until 1915 that astrophysicists would finally be able to show that, in fact, there is no planet Vulcan—the behavior of Mercury can be explained by the curvature of spacetime, which was Albert Einstein’s new way to account for the effects of gravity. Einstein’s new theory correctly predicted the orbit of Mercury.
Notice that Le Verrier was motivated in his postulates of Neptune and Vulcan to satisfy his curiosity. The existence of a new planet at that time would have almost no technological significance. He simply wanted to know why there were small deviations in the Mercurial orbit where there should not have been. Using classical Newtonian mechanics, a nearby object’s gravitational pull seemed like the most likely hypothesis. Since this hypothesis worked for deviations in the orbit of Uranus and were confirmed by the discovery of a new planet, Le Verrier had good reasons to think it would work in the case of Mercury as well.
The planet Vulcan had many supporters long after Le Verrier’s death, but the discovery of a new way to think about spacetime and gravity put this support to rest. This required intellectual honesty, for as much as people wanted to find the planet which would explain Mercury’s orbit, they had to admit there search had not been successful. It’s hard to devote your life to a hypothesis that turns out to be wrong. This means it also required some intellectual humility to admit that they were wrong, and that the 50 year quest for Vulcan had been in vain.
But this does not mean the end of curiosity! Curiosity is such that we can be mistaken in what we thought was true, and use our mistake as fuel to start moving a new direction to see what we can discover. Our curiosity should never be based on being right, but on wanting to figure things out. Le Verrier was equally virtuous in his search for Vulcan as he was in his search for Neptune, even though he was right in one case and wrong in the other.
All of the aforementioned virtues are worth cultivating. But there is one more worth reminding ourselves is a virtue: charity. Recall in section 1.1 "The Principle of Charity" that we discussed the Principle of Charity. Review that for a slightly more complete discussion of the virtue of charity.
To be charitable is to attribute the best intentions and strongest justifications to someone else. To interpret a set of actions charitably is to try to see those actions in terms of the most reasonable set of motivations or intentions behind them. To interpret someone’s beliefs charitably is to attribute moral innocence to them as a person as far as is possible so as to give them the strongest possible benefit of the doubt. Only when you have really good reasons for doing so might you think of someone else as irrational, vicious (in the sense meaning the opposite of virtuous), or petty. Charity, then, is a habit of interpreting actions and beliefs in a good light—a rational and moral light.
All of these dispositions have their appropriate limits, of course: many beliefs and actions are just wrongheaded or irrational or bigoted and we needn’t bend ourselves in pretzel knots trying to interpret them charitably. Many of our own beliefs are things we have really good reason for believing, so we don’t need to be so humble that we refuse to believe anything. Some of us, furthermore, are really in a better position to know things and to reason about them. A false sense of humility stops being honest at a certain point.
 Alfred North Whitehead, Modes of Thought. New York: The Macmillan Co., 1938, p. 16.